1. Field of the Invention
This invention is concerned with the manufacture of power transmission belts.
2. Description of the Prior Art
In one conventional form of power transmission belt, the belt is defined by an inner compression section, an outer tension section, and intermediate longitudinally extending tensile strength cords. In one form, such a belt defines a V-belt having converging side surfaces. In another form, the belt comprises a multiribbed belt wherein the inner portion of the belt is provided with one or more longitudinally extending notches, or grooves, dividing at least a portion of the compression section into a plurality of side-by-side belt elements adapted to be received in a pulley groove.
In the conventional belts of this type, the compression section and tension section are conventionally formed of rubber or the like. In one form of such a belt as shown in the Jensen et al U.S. Pat. No. 3,416,383, one or more layers of fabric are provided in the compression or tension sections. The fabric layers may be untreated or coated with rubber on one or both sides. The elastomeric layers laminated between the fabric layers may have embedded therein discrete fibers extending transversely to the belt. The fabric layers, as disclosed in Jensen et al, may be stress-relieved by having the warp and weft threads thereof disposed at an angle of between 95.degree. and 155.degree. with each other when viewed in the direction of the longitudinal axis of the belt.
Waugh et al disclose in U.S. Pat. No. 3,478,613, a V-belt which is similar to the belt of Jensen et al discussed above in having one or more layers of fabric disposed in the compression and tension sections.
In U.S. Pat. No. 3,564,933 of Donald E. Clinkenbeard, a banded power transmission belt is disclosed wherein a plurality of rib elements are maintained in spaced side-by-side relationship by interconnecting outer band formed of one or more layers of fabric embedded in an elastomer, with the threads of the fabric being bias laid, i.e. diagonal to the longitudinal extent of the belt.
Delyn M. Stork discloses in U.S. Pat. No. 3,948,113 a multiribbed power transmission belt wherein the band is formed of rubberized woven fabric material, such as cotton, polyester, or nylon, or combinations thereof.